## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$\text{Set Builder Notation: } \left\{ t|t\lt-3 \right\} \\\text{Interval Notation: } \left( -\infty,-3 \right)$
Dividing both sides by a negative number (and consequently reversing the inequality symbol), then \begin{array}{l}\require{cancel} -5t\gt15 \\\\ t\lt\dfrac{15}{-5} \\\\ t\lt-3 .\end{array} Hence, the solution set is \begin{array}{l}\require{cancel} \text{Set Builder Notation: } \left\{ t|t\lt-3 \right\} \\\text{Interval Notation: } \left( -\infty,-3 \right) .\end{array} In the graph, a hollowed dot is used for $\lt$ or $\gt.$ A solid dot is used for $\le$ or $\ge.$